Widely tunable external cavity diode lasers (ECDLs) with a narrow linewidth have become a powerful tool for a variety of applications. The difficulty of the present generation of ECDLs is that they are designed as laboratory instruments and are limited due to their size, high costs, and sensitivity to external influences. In this paper, we present our new ECDL design based on a microelectromechanical system (MEMS) device. This design overcomes the previous drawbacks and offers an outstanding improvement of the most important properties. Moreover, it can be adapted to any wavelength of interest and by using MEMS technology, costs can be reduced.